package libra;

import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;

import org.springframework.cloud.client.ServiceInstance;
import org.springframework.stereotype.Component;

/**
 * 自定义负载均衡，方式二
 * 		基于纯手写实现负载均衡策略的方式，实现自定义负载均衡算法实现
 */
public class MyLB {
	private AtomicInteger atomicInteger = new AtomicInteger(0);

	public final int getAndIncrement() {
		int current;
		int next;
		do {
			current = this.atomicInteger.get();
			next = current >= 2147483647 ? 0 : current + 1;
		} while (!this.atomicInteger.compareAndSet(current, next));
		System.out.println("*****第几次访问，次数next: " + next);
		return next;
	}

	// 负载均衡算法：rest接口第几次请求数 % 服务器集群总数量 = 实际调用服务器位置下标 ，每次服务重启动后rest接口计数从1开始。
	public ServiceInstance instances(List<ServiceInstance> serviceInstances) {
		int index = getAndIncrement() % serviceInstances.size();
		return serviceInstances.get(index);
	}
}